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LTI Troubleshooting

Please note: The information provided here is intended only to assist with integrating our product into an LMS. Our Help Site is not a comprehensive guide to use of the third-party systems mentioned here, and our team can only assist with Credo integration; we are unable to provide support for any other aspect of these systems' functionality.

Having trouble with your LTI links? Here are some common LTI integration issues and their solutions. Our support team is also available to assist with any questions you may have - simply email support@credoreference.com with a brief description of the issue and a screenshot of the error.

Error Codes

400 Your LMS Sent a Bad Request

This error message is indicative of a configuration issue. Since LTI links are specifically for use in this kind of integration, they do not work the same way a normal hyperlink usually would. you cannot add them as HTML links or copy+paste them into your browser address bar -- this is the result if you do:

BAD REQUEST (400). Your LMS sent a request that this server could not understand.

This error message can appear if the link has not been set up properly or if there is an issue with the global tool settings.

If you see this message, try the following:

1. Make sure the link is configured as an external tool/LTI link

The exact steps for adding an LTI link to a course are different depending on what LMS you use. Make sure that you have followed the correct steps for your system - follow these links for detailed instructions.

Blackboard - In Blackboard, the link is added as a Web Link. Make sure the box for "This Link is to a Tool Provider" is checked.

Canvas- In Canvas, the link is added as an Assignment. Make sure that the submission type is "External Tool."

D2L - In D2L, the LTI links are created in the "Manage external learning tool links" section first, then added to a course module. Make sure you first configure the external tool link, then, in your course content, use Add Existing Activities > External Learning Tools > LTI Link to add the existing link.

Moodle - In Moodle, the steps are to open the "Add an Activity" drop down menu and use the "External Tool" option.

2. Make sure the domain of the Launch URL matches the Launch Domain in the Tool Settings

In the Tool Provider/External App settings, you should have a Launch Domain configured. The LTI link you're adding to a course, also called the Launch URL, should use the same domain. Here is an example of a Launch Domain and Launch URL that are matched:

Verify that the key and secret saved in the Tool Provider settings are correct and that the LTI link is configured to use the Tool Provider key and secret, as described below.

4. Check the link description box for formatting issues

In some systems, such as Blackboard, having special formatting or images embedded in the "Link Description" box can prevent the LTI link from launching properly. Make sure that the description box contains only plain text.

5. Check with support!

We can help determine where the configuration issue is and how to remedy it. Sending screenshots of your Tool Provider configuration and an example LTI link configuration will help us triage the issue. We can be contacted at support@credoreference.com.

403 Forbidden

A 403 error message looks like this:

FORBIDDEN (403). Your LMS sent a request that this server could not understand.

If you see this message, check to make sure that you have entered the key and secret correctly in the tool provider setup. See below for more information.

404 Page Not Found

If you are seeing a "Page Not Found" error when trying to launch an LTI link, this indicates that the LTI Launch URL is not valid. Check the following to make sure you are using the correct link:

1. Make sure you are using an LTI link

LTI integration requires that you use specific LTI links, which are different from the URLs that you would use for hyperlinking from a LibGuide or other website. On your Instruct admin dashboard, LTI links are provided on the "LTI Links" tab - make sure you are using the links from this tab, not the "Deep Links" or "Embed Codes" tab.

2. Make sure the link has been copied correctly

Copy-paste errors can sometimes truncate the end of the URL, which will break the link. LTI links also cannot have a trailing slash (a forward slash, /, at the end of the URL).

3. Make sure the content is visible to users

Admins can use their editing permissions to make content hidden from users, so that it can be viewed by admins but not by students. When a content item is hidden, links used for student access (LTI links, deep links, embed codes) will result in a "Page Not Found" error. If this occurs, you can make the content visible in Studio, or simply not link to that piece of content.

The "Promoting the Modules" content section is hidden by default but can be made visible if you choose.

4. Check with support!

If you have verified that you have copied the link correctly from your admin dashboard and still see this error, contact us at support@credoreference.com -- we will check for other problems with your links.

Blank Screen

If you're seeing a blank screen when trying to launch an LTI link, with no error message appearing, here are some settings to check:

1. Key and Secret

Verify that the key and secret saved in the Tool Provider settings are correct, as described below.

2. Tool Settings

Privacy and security settings can impact whether or not the LTI connection launches successfully. Make sure that you have configured your settings as described on the set-up instructions for your LMS. In particular check the following:

Your privacy settings must allow the student's name and email address to be sent to Credo over the LTI connection, or the integration will not work.

If your institutional firewall requires you to access outside websites via SSL, you may need to tick a box that forces the tool via SSL.

For detailed instructions on the settings to use for your LMS, see the following links:

Links should be configured to use the privacy and security settings defined by the global Tool Provider/External App set-up. In Moodle, Blackboard, and Canvas, this should be automatic as long as the Tool Provider is set up correctly. In D2L, this must be configured as described here.

4. Check with support

If the above steps don't help, consult with us at support@credoreference.com and we can verify that your settings match our recommended set-up. If further troubleshooting is needed, we may refer you to your LMS vendor's support team for assistance; since your LMS is a third-party system, we do not have the internal knowledge or access to back-end systems that your vendor's support team can use to diagnose the problem.

Grades Not Syncing

If your students are able to access the content, but their quiz grades are not syncing to the course gradebook, there could be a configuration error in your LTI set-up. You can use the following steps to make sure the grade passback and gradebook columns are configured correctly. If these steps don't help, please contact Credo support at support@credoreference.com so that we can assist you further.

The column for the quiz should be generated in the course gradebook automatically after the first user takes the quiz. You should not manually create a column.

Canvas

1. Tool and Link Settings

Make sure that the privacy on the external app is set to "Public" (see screenshot). Also make sure that you've added the LTI link to your course as an Assignment.

2. Gradebook Column

The column for the quiz should be generated in the course gradebook automatically after the first user takes the quiz. You should not manually create a column.

D2L

1. Configuring a Gradebook Column

In D2L, you must manually set up a Gradebook column after configuring a link. The instructions for doing so can be found here.

Moodle

1. Tool and Link Settings

In the External Tool Configuration, the "Accept grades from tool" option must be set to "Always." See a screenshot here.

In the link settings, make sure you have set the "External Tool Type" of the link to "Automatic, based on Launch URL", as shown here.

2. Gradebook Column

The column for the quiz should be generated in the course gradebook automatically after the first user takes the quiz. You should not manually create a column.

3. Maximum Grade Setting

If student grades are appearing in the Grade Book as a zero, check the LTI link's settings to confirm that a maximum grade value has been set. The grade passed back by LTI will scale according to how many points it has been assigned, so if the maximum grade is set to zero, all students' grades will show as zero.

To check, open Edit Settings for the quiz in question, open the Grade toggle, and check the maximum grade value.

Common Elements to Check

Key and Secret

A consumer key and secret are provided on your Instruct admin dashboard for use in the Tool Provider set-up. The key and secret are necessary for ensuring that your LMS connects properly to our system and allow student access. Make sure that you have copy+pasted the key and secret correctly into the appropriate fields in the Tool Provider/External App configuration.

In a correct set-up, the key and secret are saved in the Tool Provider/External App settings, and the LTI link, when added to a course, is configured to use that saved key and secret. It is also possible to add the key and secret directly in the link configuration, but this is not normally recommended if you've already added it to the global Tool Provider set-up.

The settings and terminology vary depending on your LMS, so see below for settings to check in your system:

Moodle - Make sure you have set the "External Tool Type" of the link to "Automatic, based on Launch URL", as shown here.

D2L - In "Manage External Learning Tool Links", go into the link settings and make sure that the "Sign message with" option is checked and set to "Tool consumer key/secret", as shown here.

In Blackboard and Canvas, the link will automatically use the Tool Provider key/secret as long as the link domain matches the Tool Provider domain.

If you have checked the key and secret on both the Tool Provider and the LTI link settings, contact support@credoreference.com so that we can double-check your key and secret, and generate a new set for you if necessary.

Launch Domain and Launch URL

Before adding LTI links to a course, a global configuration is required to add Credo as a Tool Provider in your LMS. In this configuration, you identify the Launch Domain that will be used by all of the LTI links for Instruct.

The LTI links you add to a course, also called the Launch URLs, should use the same domain. This will match the URLs with the Tool Provider you configured.

The exact steps and terminology used for this process differ depending on your LMS. Here is an example from Canvas.

In Canvas, the Tool Provider setup is done by adding Credo as an "External App." In this example, this has been configured with frame.credocourseware.com as the launch domain.

When an LTI link is added as an assignment in a course, it uses this same domain:

If these two domains don't match, you must make sure you are using the correct domain and LTI links as provided on your Instruct admin dashboard. If you're not sure, send an email to support@credoreference.com and we can assist.

For detailed instructions on Tool Provider/External App set-up for your LMS, see the following links: